Ultrathin Si/CNTs Paper-Like Composite for Flexible Li-Ion Battery Anode With High Volumetric Capacity.

Jinzhou Fu,Yun Hai,Lefu Mei,Hao Liu,Zhen Wang,Jie Xing,Ziwei Zhang,Peng Fan,Libing Liao,Guocheng Lv,Yuanyuan Wu,Huiying Hao,Jingjing Dong

doi:10.3389/fchem.2018.00624

Jinzhou Fu, Yun Hai + Show 11 more

Open Access

https://doi.org/10.3389/fchem.2018.00624

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Abstract

Thin and lightweight flexible lithium-ion batteries (LIBs) with high volumetric capacities are crucial for the development of flexible electronic devices. In the present work, we reported a paper-like ultrathin and flexible Si/carbon nanotube (CNT) composite anode for LIBs, which was realized by conformal electrodeposition of a thin layer of silicon on CNTs at ambient temperature. This method was quite simple and easy to scale up with low cost as compared to other deposition techniques, such as sputtering or CVD. The flexible Si/CNT composite exhibited high volumetric capacities in terms of the total volume of active material and current collector, surpassing the most previously reported Si-based flexible electrodes at various rates. In addition, the poor initial coulombic efficiency of the Si/CNT composites can be effectively improved by prelithiation treatment and a commercial red LED can be easily lighted by a full pouch cell using a Si/CNT composite as a flexible anode under flat or bent states. Therefore, the ultrathin and flexible Si/CNT composite is highly attractive as an anode material for flexible LIBs.

Highlights

Flexible electronic products, such as wearable electronics, smart textiles, rollup displays, bendable mobile phones, and implantable medical devices, are developing at a tremendous pace (Stoppa and Chiolerio, 2014; Zhou et al, 2014; Pu et al, 2015; Liang et al, 2017a,b, 2018)
Si was electrodeposited on the carbon nanotube (CNT) substrate in a non-aqueous electrolyte solution using a three-electrode system (Nicholsonz, 2005; Nishimura and Fukunaka, 2007; Munisamy and Bard, 2010; Liu et al, 2013; Osaka et al, 2014)
During the preparation of the Si/CNTs composite, a constant current density of −3 mA cm−2 was employed for Si electrodeposition

Summary

Introduction

Flexible electronic products, such as wearable electronics, smart textiles, rollup displays, bendable mobile phones, and implantable medical devices, are developing at a tremendous pace (Stoppa and Chiolerio, 2014; Zhou et al, 2014; Pu et al, 2015; Liang et al, 2017a,b, 2018). The discharging and charging volumetric capacities of Si/CNT-4 in the first cycle are 2,438 mAh cm−3 (4,434 mAh g−1) and 1,146 mAh cm−3 (2,084 mAh g−1), respectively, corresponding to an initial coulombic efficiency of ∼47%.

Results

Conclusion